• 대한안전경영과학회지
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• 제9권6호
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• pp.89-96
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• 2007

It is well known that the test and evaluation plan (TEP) is very crucial in the successful development of safety-critical systems. As such, this paper discusses an approach to the development of the TEP for a system that should meet safety requirements in the systems development process. It is studied how to incorporate the result of preliminary hazard analysis (PHA) in generating the safety requirements. It is also discussed how to deal with them when the system requirements (i.e., functions, performance, constraints, components, etc) and the safety requirements are integrated into one model. While doing so, we have constructed the required traceability among them, which is necessary and very useful when the safety requirements need to be corrected or be changed. The use of the traceability makes it possible to easily check out whether and how the safety requirements are properly incorporated in the system design process. Furthermore, without the verified traceability, the system cannot be changed or upgraded later. In order to implement the model on a computer-aided tool, we have constructed a database (DB) schema. As a result, the implemented model/DB allows to automatically generate TEP which can be used to measure the performance and safety level of the developed system.

• 항공우주시스템공학회지
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• 제8권3호
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• pp.47-54
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• 2014

This is a research on the method of how to improve stall characteristics for the small general aviation airplanes to meet the FAR part 23 requirements. This research is based on the experience of certification flight tests of KC-100 airplane for Korea type certification. KAS/FAR Part 23.201/203 are the stall characteristics requirements. 23.201 requires to show the stable stalling tendency of the wings level stall and 23.203 requires to show the stable stalling tendency of stall characteristics during turning flight. In this paper, the stall characteristics requirements, improvement methods and flight test experience of KC-100 airplane for type certification.

• 산업공학
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• 제16권1호
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• pp.70-84
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• 2003

Recently, object-oriented techniques have been used more and more for developments of an information system. But, established object-oriented methodologies are hard to express a business process of various abstract degrees in the analysis level and independent components of the system. They have difficulties in developing a large-scale information system of manufacturing industry such as PDM and CIM. This paper proposes an information system development methodology that imports the object-oriented IDEF0 (OOIDEF0) function model in analysis level. This methodology is made up of requirements gathering, system analysis, system design, and implementation. In requirements gathering level, organization diagram and interview technique are used for input data of OOIDEF0 function model. The OOIDEF0 function model, the interface model and function descriptions are made out in analysis level. Information objects and implementation objects are designed on the basis of the OOIDEF0 function model in design level. The database is built and programming is accomplished in implementation level. In order to prove the consistency and efficiency of the proposed methodology, the PDM system for ship production is modeled and prototyped.

• Steel and Composite Structures
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• 제50권6호
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• pp.643-658
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• 2024

The main aim of this study is to quantify the code seismic design coefficients of the RCS system, which consisted of reinforced concrete columns and steel beams, based on the FEMA P-695 methodology. The underlying intention is to evaluate the seismic performance of the RCS system at the system level rather than the connection level. A set of 24 archetype buildings with a various number of stories, beam span lengths, gravity load levels, and seismic load levels are selected and designed based on the prevailing code requirements. Nonlinear analytical models are developed and validated by experimental tests. The pushover and response history dynamic analyses are conducted to evaluate the required data in the performance quantification process. The results show that the design coefficients suggested by the code are acceptable. However, the level of conservatism is very high. Thus, it is possible to use a larger R-factor in the design process or make some relaxations in the design requirements related to this structural system.

• 산업경영시스템학회지
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• 제37권4호
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• pp.24-34
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• 2014

In order to manage essential parts that are required for the repairable parts services performed at the military maintenance depots, the United States Air Force developed the Repairability Forecasting Model (RFM). In the RFM, if the requirements of the parts are assumed to follow the normal probability distribution after applying means from the past data to the replacement rate and lead times, the chance of the AWP (Awaiting Parts) occurring is 50%. In this study, to counter the uncertainties of requirements and lead times from the RFM, the safety level concept is considered. To obtain the safety level for requirements, the binomial probability distribution is applied, while the safety level for lead time is obtained by applying the normal probability distribution. After adding this concept, the improved RFM is renamed as the ARFM (Advanced RFM), and by conducting the numerical stimulation, the effectiveness of the ARFM, minimizing the occurrence of the AWP, is shown by increasing the efficiency of the maintenance process and the operating rate of the weapon system.

• 시스템엔지니어링학술지
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• 제1권2호
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• pp.56-62
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• 2005

In this study, we first define user requirements to fulfill the reconnaissance and the search missions, by analyzing the system characteristics and operation environment. By investigating the design technology level, the development and procurement costs, the strong system design concepts and possible alternatives will be proposed. To analyze the system requirements, the Quality Function Deployment of the systems engineering approach will be implemented. The promising design alternatives that satisfy the user requirements are extracted by constructing the Morphological Matrix, then the best design concept will be obtained using the Pugh Concept Selection Matrix and the TOPSIS(Technique of Order Preference by Similarity to Ideal Solution).

• 반도체디스플레이기술학회지
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• 제22권1호
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• pp.88-93
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• 2023

In software engineering, requirement analysis is an important task throughout the process and takes up a high proportion. However, factors that fail to analyze requirements include communication failure, different understanding of the meaning of requirements, and failure to perform requirements normally. To solve this problem, we derived actors and behaviors using morpheme analysis and BERT algorithms in the Korean requirement document and constructed them as ontologies. A chatbot system with ontology data is constructed to derive a final system event list through Q&A with users. The chatbot system generates the derived system event list as a requirement diagram and a requirement specification and provides it to the user. Through the above system, diagrams and specifications with a level of coverage complied with Korean requirement documents were created.

• 대한임베디드공학회논문지
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• 제4권2호
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• pp.50-54
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• 2009

In this paper, we address a novel system-level power management technique which is specifically targeted for an ARM 11 MPCore system. Our proposed solution is a DPM technique which includes process monitoring, real time power analysis, and policy application to reduce the power consumption while meeting the performance requirement. One of the main contributions of this paper is that we systematically infer QoS requirements of processes without getting any additional information from the application. When multiple processes are running under various user level policies, priorities of the policy application are determined in such a way that the overall system performance is maintained while power consumption is effectively managed. Experimental results show that our DPM technique is very effective in reducing power consumption without violating system's QoS requirements.

• 한국CDE학회논문집
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• 제21권3호
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• pp.313-324
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• 2016

As building information modeling (BIM) is expanding its influence in various fields of architecture, engineering, construction and facility management (AEC-FM) industry, BIM-based automated code compliance checking has become possible prospects. For the automated code compliance checking, requirements in building code need to be processed into explicit representation that enables automated reasoning. This paper aims to develop high-level methods that translate verb phrases into explicit representation. The high-level methods represent conditions, properties, and related actions of the building objects and clarify the core content of the constraints. The authors analyze building permit requirements in Korea Building Code and establish a standardized process of deriving the high-level methods. As a result, 60 kinds of the high-level methods were derived. In addition, method classification, analysis, and application are introduced. This study will contribute to the representation of explicit building code sentences and establishment of the automated building permit system of Korea.

• Journal of the Optical Society of Korea
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• 제20권6호
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• pp.704-715
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• 2016

In this paper, we explore a low-complex bandwidth allocation (BA) scheme with multi-level service guarantees in VLC-OFDM systems. Effective capacity theory, which evaluates wireless channel capacity from a novel view, is utilized to model the system capacity under delay QoS constraints of the link layer. Since intensity modulation of light is used in the system, problems caused by frequency selectivity can be neglected. Then, the BA problem can be formulated as an integer programming problem and it is further relaxed and transformed into a concave one. Lagrangian formulation is used to reformulate the concave problem. Considering the inefficiency of traditional gradient-based schemes and the demand for distributed implementation in local area networks, we localize the global parameters and propose a quasi-distributed quadratic allocation algorithm to provide two-level service guarantees, the first level is QoS oriented, and the second level is QoE oriented. Simulations have shown the efficient performance of the proposed algorithm. The users with more stringent QoS requirements require more subcarriers to guarantee their statistical delay QoS requirements. We also analyze the effect of subcarrier granularity on the aggregate effective capacity via simulations.